<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <style>
        .ibm{
            background-color: blue;
        }

        .bg{
            background-color: aquamarine;
        }
    </style>

</head>
<body>
    <div>111</div>
    <div class="ibm">222</div>
    <div class="bg">333</div>
    <div>444</div>
    <div>666</div>
    
</body>
</html>